Facebook have confirmed this, but have insisted that the information collected is only for security purposes or to aggregate statistics. Facebook's data collection is from the cookies on your computer when you visit the social network, with the cookies shifting the information over to Facebook from any site that you visit that contains a link to Facebook - such as the "like button".

With this information in-hand, Facebook can map out your web usage. Director of Engineering for Facebook, Arturo Bejar, has said that the data is used to combat spam and phishing attacks by detecting suspicious logins. Not only that, but cookies can use the data to keep users from having to complete extra authentication steps each time they log-in. Because, you know, everyone logs out of Facebook when they're finished with it.

Most people, like myself, would expect that once logged out, communication between the device you're on and Facebook is severed - over, off, finished. But, it look like this is not the case. A Facebook spokesman has said "no information we receive when you see a social plugin is used to target ads."

There are ways around this, by using a separate browser for Facebook. So, if you're a Google Chrome user - install Firefox and use Facebook only within Firefox and do everything else within Chrome. The problem with that is you shouldn't have to do that - once you're logged out of Facebook, that should be it for data collection, period.